Omg YES SO MUCH THIS because there have been exchanges throughout history (and before recorded history) between East and S/SE Asia! One study found that 20-30% of Koreans have Southeast Asian heritage through the paternal line, and you can tell from the difference in looks, too. There have been historical records of intermarriage as well: It is said that King Suro, who ruled the Kingdom of Garak (unrelated to Elim Garak the Cardassian spy) in the southeast of modern Korea, married a princess of Ayodhya in the north of modern India. This was way back in the 1st-2nd century AD!

Now, this far back history gets muddled and mixed up with myth, and the same record also says Suro and his wife both lived to be 157 years old so it’s probably best to take everything with a grain of salt. Some have said that while Suro did marry a princess who traveled from a faraway land, attributing to her the background of an Ayodhyan princess is likely to be a later addition after Buddhism came to Korea a few centuries later. This, of course, shows in a backhanded way the awareness of and prestige attached to India.

Though not S/SE Asia per se, there has been active exchange with Central Asia and the Middle East as well. The reason we use the name “Korea” to refer to this peninsula is because of Arab merchants who who traded in select ports and spread the name. “Korea” comes from Goryeoh btw, the kingdom that ruled most of the peninsula from 10th-14th century.

It has also been suggested that a major figure in Korean religion and mythology, Cheo-Yong, was originally an Arab or Persian man who settled in Korea for a while and married a Korean woman. There’s a similar Persian story of an exiled Persian prince marrying a Korean princess.

Long story short, the history of exchanges with parts of the world outside of China and Japan is an area that’s extremely understudied in Korea and there’s a whole book on the subject of exchange between Korea and SE Asia that I’m excited to read! Let’s definitely talk more and swap info.